Project Summary. Low back pain imposes a high burden in terms of morbidity and healthcare spending. From a policy standpoint, there are two important issues. First, many patients with low back pain ultimately transition into chronic opioid use, with its resulting effects on mortality, morbidity, and healthcare spending. Second, the cost-effectiveness of many treatments for low back pain has not been fully characterized. The long-term goal of this project are to (1) characterize the economics and epidemiology of chronic opioid use among patients with low back pain, (2) evaluate whether therapeutic procedures (such as epidural steroid injections) reduce opioid use and healthcare spending, and (3) evaluate the cost-effectiveness of alternative treatments for low back pain. Accomplishing these goals will inform policymakers and payers about the epidemiology and economics of low back pain, and improve policymaking, for example by helping to guide payment policies for low back pain treatments. For this particular application, the objectives are to use administrative health claims data from Medicare to: (1) characterize opioid use trajectories in elderly patients with low back pain as well as patient/provider factors that affect these trajectories, (2) analyze the effectiveness of Epidural Steroid Injections (ESIs) in reducing opioid use and healthcare spending among these patients and (3) analyze the cost-effectiveness of Epidural Steroid Injections. This research is innovative in its use of large databases and sophisticated statistical approaches to provide definitive answers to the questions described above. It is significant because of its comprehensive approach towards addressing several policy- and clinically-relevant questions of compelling interest and of interest to the NIDA. In addition to the research objectives outlined above, this project will also allow the candidate to achieve his long-term goal of becoming an independent investigator in health economics/policy with a particular focus on the economics of chronic pain. Specifically, the project will aid the candidate?s development by (1) increasing his experience and background in pain research, addiction medicine, and non-pharmacologic pain treatments and (2) giving the primary investigator the didactic training and experience needed to perform cost-effectiveness studies using tools from decision science. The project leverage the strengths of Stanford University, such as a multidisciplinary mentoring team uniquely tailored to the candidate?s interests and background. In addition, it takes advantage of an existing PhD program in Health Policy (with a specific track in decision science) to provide the didactic training and practical experience the candidate requires in order to learn decision science and transition into a career as an independent investigator. With this training and experience, the candidate will be uniquely positioned to use tools from his prior background in economics, as well as the tools of decision science, to seek further funding that will evaluate the effectiveness of other treatments?as well as policies in general--in reducing opioid use and treating chronic pain.